Question

Calculate the IV flow rate in \(\mathrm{gtt} / \mathrm{min}\) for the following IV administrations, unless another unit of measure is stated. Order: Levaquin \(500 \mathrm{mg}\) IVPB in \(100 \mathrm{~mL} 0.9 \%\) NS q \(12 \mathrm{~h}\) over \(1 \mathrm{hr}\). Drop factor: \(10 \mathrm{gtt} / \mathrm{mL}\) Determine rate in \(\mathrm{gtt} / \mathrm{min}\).

Short answer

17 gtt/min.

Step-by-step solution

Identify the Given Information

To calculate the IV flow rate, we need to identify the key pieces of information given in the problem. The order specifies that the medication is Levaquin 500 mg IVPB in 100 mL of 0.9% Normal Saline to be infused over 1 hour. The drop factor provided is 10 gtt/mL. We need to calculate the flow rate in gtt/min (drops per minute).

Convert Hours to Minutes

Since the order specifies that the infusion is to occur over 1 hour, we need to convert this time into minutes. There are 60 minutes in 1 hour, so the infusion time is 60 minutes.

Calculate the Flow Rate Formula

The flow rate (\( R \)) in gtt/min can be calculated using the formula:\[ R = \frac{{ ext{{Total volume to be infused (mL)}}}}{{ ext{{Infusion time (min)}}}} \times \text{{Drop factor}} \, \left( \frac{{ ext{{gtt}}}}{{ ext{{mL}}}} \right) \].

Calculate Volume Infusion Rate

Insert the known values into the formula: Total volume is 100 mL, time is 60 minutes, and drop factor is 10 gtt/mL:\[ R = \frac{100}{60} \times 10 \].

Perform the Calculation

Now perform the calculation to find the rate:\[ \frac{100}{60} = 1.6667 \] Then, multiply by the drop factor:\[ 1.6667 \times 10 = 16.667 \].

Round to the Nearest Whole Number

IV flow rates are typically rounded to the nearest whole number because you can't administer a fraction of a drop. So round 16.667 to 17 gtt/min.

Key concepts

Drop Factor

The drop factor tells us how many drops make up one milliliter of fluid. It's usually given as "gtt/mL," where "gtt" stands for "gutta" – the Latin word for "drop." Drop factors are important because they can vary based on the type of IV tubing used.
For example, macrodrip sets have a drop factor between 10 and 20 gtt/mL, suitable for adults or when you're infusing fluid quickly. Whereas microdrip sets have a drop factor of 60 gtt/mL and are useful in pediatric or neonatal care, where precise flow rates are crucial.
In our exercise, the drop factor is 10 gtt/mL. Before calculating the flow rate, identify this number, as it is essential in determining how many drops per minute are needed.

Infusion Time

Infusion time is simply the duration over which the fluid is meant to be administered. Knowing this helps ensure that the medication is given at the right pace, not too fast or too slow.
The time is typically given in hours, minutes, or a combination of both. For calculations, it's crucial to convert everything into the same unit.
In the exercise, the Levaquin needs to be infused over one hour. One important step in calculations is converting hours to minutes since flow rates are calculated in minutes. One hour is equal to 60 minutes, and that's the number we'll use in the flow rate formula.

Flow Rate Formula

The flow rate formula helps you determine how fast you need to administer the IV solution. This is essential for effective patient care and ensuring that patients receive their medications at a safe rate.
The formula to calculate the flow rate (\( R \) ) in drops per minute is:\[ R = \frac{\text{Total volume to be infused (mL)}}{\text{Infusion time (min)}} \times \text{Drop factor} \left( \frac{\text{gtt}}{\text{mL}} \right) \]This formula uses basic division and multiplication to express how many drops per minute are required. In our example, with a 100 mL volume, a 60-minute infusion time, and a drop factor of 10 gtt/mL, you can plug these numbers into the formula to get the flow rate.
This gives \[ \frac{100}{60} \times 10 = 16.67 \text{ gtt/min} \]. After rounding, as it's not possible to administrate fractions of a drop, we end up with approximately 17 gtt/min.

Intravenous Therapy Calculation

Intravenous therapy calculation is a critical skill in healthcare settings, ensuring medications are delivered safely and effectively. Accurate calculations prevent under-infusion or over-infusion, which can have serious repercussions for patient health.
Before starting any IV infusion, healthcare professionals need to carefully read and interpret the orders. This includes verifying the prescribed dosage, total volume of the solution, and the time over which it needs to be infused.
For successful intravenous therapy calculation, attention to detail is key. By following methodical steps, as seen in the exercise, you can ensure the right amount of fluid is administered at the right rate indicated by the flow rate you calculated. Skipping any part, such as converting time units, could lead to errors, highlighting the importance of precision in this type of calculation.